41 1 <0.001 Field width + 5.87 1 0.015 Detrivores Ln(abundance) Age of field margin + 8.732 1 0.003 In all cases farm and year of sampling

were included in the random model. The model estimates are represented graphically in Figs. 2 and 3 NR not relevant Fig. 2 Mean number of taxonomic invertebrate groups (±SE) per age of field margin category. Estimated means and standard errors are based on the HGLM model with age as categorical variable. Trend is based on the same model with age as scale variable. Trend is significantly different from zero (Table 1B) Abundance of functional groups In total, 34,038 predator, Selleck LY333531 11,305 herbivore and 10,720 detritivore individuals were caught with the pitfall traps. Predator abundance was significantly affected by the age category of the field margin (Table 1A); the abundance of predators

decreased with increasing age of the margin (Table 1B; Fig. 3). Herbivore abundance was significantly related to vegetation cover in summer, margin width and age category (Table 1A). A positive relationship with the age of the margin was found (Table 1B; Fig. 3). Detritivore abundance was not affected by age category (Table 1A), but a clear positive correlation between age of the margin and detritivore abundance was found (Table 1B; Fig. 3). Fig. 3 Mean number of individuals of predators, herbivores and detritivores (±SE) per age of field margin category. Estimated means and standard errors are based on the HGLM model of the Ln-transformed Selleckchem RXDX-101 Farnesyltransferase abundance data after correcting for other significant factors and with age as categorical variable. Trends are based on the same model with age as scale variable. All trends are significantly different from zero (Table 1B) Field margin variables Several site-specific variables showed significant relationships with the

age of field margins (Table 2): we found a decrease in the number of plant species (t = −5.585, P < 0.001) and in their evenness (t = −2.651, P < 0.001), the latter indicating that the vegetation is moving towards dominance by certain species. The vegetation cover in summer increased (R = 0.521, P < 0.001). No trends could be detected for nutrient richness, vegetation height in summer and winter, and vegetation cover in winter. Table 2 Significant relations between field margin age and site-specific variables; in a few cases, data for certain margins were lacking (number of replicates is given below each average) Variable (unit); transformation, test Age 1 2 3 4 5 6 7 8 9 10 11 Sign (Back-transformed) averages (Replicates) Plant species (total number); Ln(x + 1), linear regression t = −5.585 − 18.683 15.653 9.137 17.014 11.375 9.781 8.582 5.989 6.937 10.917 11 P < 0.001 (27) (23) (4) (11) (16) (20) (12) (6) (2) (9) (1) Plant species evenness (E var); untransformed, linear regression t = −2.651 − 0.743 0.614 0.428 0.631 0.620 0.574 0.662 0.470 0.490 0.629 0.63 P < 0.